Cancer has been treated with radiopharmaceuticals for 80 years. A recent National Cancer Research Institute report from the Clinical and Translational Radiotherapy Research Working Group reviews the current status of molecular radiotherapy and has highlighted the barriers to and opportunities for increased research activities. The report recommends a number of actions to promote this field, which in the dawning age of personalized medicine and theragnostics is of increasing importance, particularly with the clinical introduction of a range of new commercial radiotherapeutics at costs in line with those seen for conventional chemotherapeutics. These recommendations recognize the importance of a multidisciplinary approach to the development of molecular radiotherapy and the particular need for investment in radiopharmacies and personalized dosimetry. There are many areas to be investigated including adaptive treatment planning, the use of radiosensitizers and translational radiation biology. Progress in these areas will result in significant patient benefit and more cost-effective use of increasingly expensive therapeutic radiopharmaceuticals. A concerted effort from the community, from funding bodies and from health service providers is now needed to address the scientific and logistical changes necessary to realize the potential offered by this currently underused treatment modality.